Tag Archives: sea surface temperature

BREAKING: 29 Apr 2012 Tropical Update on Developing Tropical Low 97W Off Southeastern Mindanao

By: Weatherguy Adonis

Adonis S. Manzan

Invest 97W Sprung To Life, Torrential Rainfall Threatens Eastern Mindanao

Iloilo City, Philippines, 23 April 2012, (1600Z)–For the last five (5) days in a row of intense heat associated with the prevailing “Ridge of High Pressure,” just to the Northeast of the Philippine Sea, with temperatures soaring high as 38C in most of Northern Luzon Provinces, our tenacious little Tropical Disturbance off the Southeastern edge of Palau Island, Federated Island of Micronesia has come back to life after almost defeated by the drier conditions in the past four (4) days or so. Now that Shearing levels in the Upper atmosphere remains low, and Oceanographic values remain favourable, the system has finally entered into a new phase of life as moisture-laden clouds made a push towards the West, in a line of active thunderstorms flaring across the near-Equatorial region has led to the enhanced development of Invest 97W for the last 24 hrs.

I am made to believe that the system has a lease of life since its conception between 23 April and 24 April 2012, where most of the experts on this field of meteorology would agree on the point of warming oceans breed tenacious tropical systems that are capable of traversing vast distances longer that perceived before.

In my recent post at http://www.theboplive.net, “Warm oceans are breeding grounds of intense storm systems, and those regions where precipitable amounts of water vapor are most candidate for rapid intensification, which most scientists and meteorologists agree as main cause of intensification phase rate ranging from within five (5)  to fifteen (15%) boost potential and right conditions as regards to Wind shear and terrain variables that affects the lifespan of storms and the way they are expected to behave.”

Fig. 1.0 "MTSAT IR Imagery indicating how large the lump of clouds wrapping around Tropical Disturbance 97W as it intensifies further along the Southeastern edge of Mindanao coast. Image Courtesy: RAMMB/CIRA."


Again, I am bound to follow more than an impression, but on a generational scale, indeed, these Tropical Cyclones gather immense energy derived from the “Heat,” from the world’s oceans, and other atmospheric values such as Wind shear, Upper-level winds and prevailing weather systems should correspond to seasonal wind systems that would tend to support a stable region for tropical development.
Meantime, yesterday’s severe weather across Hong Kong territory associated with a “Trough of Low,” has now developed into a “Frontal system,” just North of Basco, Batanes and Taiwan Island. The said weather system should induce some showers extending from Northwest of Laoag City, Ilocos Sur and as far as Northeast towards the Ryukus Island Group in Southern tip of Japan, to include Naha in Okinawa.

Current Position:

As of 1832Z (0232AM-PHL/MAL), Tropical Disturbance “97W” has been located at 6.0N-129.5E, approximately 470 km East-southeast of Davao City, Philippines. Winds have reached 40 km/hr near the center, barometric readings at 1006 hPa at the moment, and is tracking Northwest at 15 km/hr.

Fig. 2.0 "An MTSAT IR Imagery I got from our colleague in Germany, Mike Adcock of the US Air Force depicting the increasingly huge banding that has been happening overnight within the system. You could immediately tell that this system could potentially have greater impacts to land mass especially terrain along the coast and hinterlands and some possibility of landslides happening and flooding. Image Credit: MTSAT IR, Mike Adcock."

It is forecast to move inland along the Eastern coast of Mindanao later evening today, Sunday, 29 April 2012 through Monday, 30 April 2012 if it maintains acceleration due West-northwest. Flooding potentials of 150 mm of rainfall totals in 24-hr period upon landfall could be expected in this system as “Orographic lift,” should bring enhanced cloudiness along the coastal regions of Southern and Eastern Mindanao as of posting in line with the banding wrapping near the system’s core, LLCC. Its outer bands have already reached the Northern edges of Mindanao and more convective rain band are slowly creeping inland which covers most of Central Mindanao by dawn breaking today.

NASA’s TRMM has been indicating a hefty 67-68 mm rainfall accumulation in a 24-hr period pegged for the system at the moment while at sea, and other sources of information I got was that the purples are evidently becoming more broader as it feeds on the relatively high sea-surface temperature as part of the “Diurnal,” processes a Tropical system are expected to undergo.

Flash floods and possible landslides especially along danger zones and mountain slopes are vulnerable during a storm so people along these areas should be warned of the dangers of staying in there, and would be wise enough to prepare and follow more than instinct but better judgment by staying on alert at all times. We will never know who’s lives would be spared from another tragedy such as last year’s worst–Tropical Storm “27W/Washi,” locally known as “Sendong,” that left vast tracts of lands and cities awash by torrential rains and the deluge that followed through, killing 1,300 people and sending thousands into shelters, and damages into almost Php2.2 Billions in infrastructure and agriculture. This time, who knows who’s life would be saved, it could be yours.

Fig. 3.0 "Another closer look at the system spawning some sporadic thunderstorms across the Eastern and Southeastern periphery of Mindanao. Image Credit: RAMMB/CIRA."

I am especially proud that our weather bureau, Philippine Atmospheric Geophysical & Astronomical Services Administration (PAGASA) has been following the development since last night, and continues to do so in keeping up with the latest of the system. The Joint Typhoon Warning Center (JTWC) in Pearl Harbour, Hawaii Island,USA and the Japan Meteorological Agency (JMA) in Tokyo, Japan has yet to issue warnings on the system.

Hope all folks in Mindanao got the news, adequate, fresh and right!

More details as the system progresses further.

This would be all for now, from your Weatherguy, hailing from the Philippines! =)

With data from NRL Mry, HKO, PAGASA and Westernpacificweather.com 

 (Note: If you have queries, email me at amanzan@smartbro.net or through weatherguyadonis@theboplive.net)

02W/PAKHAR Weakens To Tropical Storm, Threatens To Make Landfall In Viet Nam On Sunday

By:  Weatherguy Adonis

Adonis S. Manzan

 

Once Formidable Storm Weakens

Iloilo City, Philippines, 31 March 2012, (0400Z)–Category 1 Typhoon no more.  Our tropical system, “02W/PAKHAR” was a Typhoon no more as the winds died down gradually weakening its core, and the intensity readings went down to Tropical Storm threshold this morning.  Winds near its center was about 75 km/hr (40 kt) and gusting to 111 km/hr (60 kt), with central pressure of 998 hPa.  Tropical Storm “02W/PAKHAR” was located near 9.6N-109.9E or approximately 376.3 km South-southeast of Ho Chi Minh City, Viet Nam.  I am considering the Japan Meteorological Agency (JMA) scale measurement at the moment.

The Joint Typhoon Warning Center (JTWC) however pegged the system to be slightly stronger that of the JMA measurement at 111 km/hr (60 kt) with higher gusts reaching 140 km/hr (75 kt), making it a “Strong Tropical Storm,” almost at “Category 1 Typhoon” threshold by scale.

At the onset, the the prevailing “Upper level winds” are consistently favourable for the system to maintain its strength, despite the variation of existence of some drier air mass coming from its Southwestern periphery and a building Subtropical Ridge (STR) that should steer the system generally Westwards later tonight before making land fall along the coast of Viet Nam later tomorrow, 01 April 2012 at about nightfall according to some Numerical models that I have been checking out from time to time.

Fig. 1.0 "Typhoon 02W/PAKHAR lost its steam as convective banding tries to consolidate. A building STR should steer it towards Viet Nam coast sometime Sunday evening. Image Credit: CIRA."

Nevertheless, the oceanographic conditions are in aide for a slow but steady intensification phase of Tropical Storm “02W/PAKHAR” as it continues to stay offshore, away from land mass, but its outer bands have already arrived in advance since yesterday so flooding should not be a question anymore.

Meteorological Agencies Scale Up 02W/PAKHAR’s Intensity

There might be some confusion around here as regards to the Japan Meteorological Agency (JMA) definition of a “Tropical Storm” versus a full-pledge “Typhoon,” which the American models indicate, and in strong agreement with other interrelated Meteorological Agency across the Asia-Pacific Region.  By no means necessary, a “Tropical Storm” using the measurement scale of the Regional Specialized Meteorological Center (RSMC) based in Tokyo, Japan, under JMA’s operation, rap it up to between 62 km/hr (34 kt) and 88 km/hr (47 kt), and it all begins to come into mind that there are deep variations to this with that of a full-pledge “Typhoon,” that translates to a higher wind acceleration reaching above 118 km/hr (64 kt).

In the light of these, it clearly indicate a substantial difference with the interpretation of wind-average readings that uses a 10-minute wind average intervals.  The JMA uses this in terms of wind intensity sustained within the 10-minute period, as per World Meteorological Organization (WMO) regulation based in Geneva, Switzerland.

In most cases, this requirement are being observed by most of the weather agencies from around the world.  The 10-minute average we call it, points to a system that analyze the winds sustained within a Tropical Cyclone at a given time at a height of 10.0 m (33 ft), to which our state weather bureau, Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA) also utilizes in reaching for a consensus in the event of a Tropical Cyclone threatening the Philippines within its Philippine Area of Responsibility” (PAR).

Fig. 2.0 "An impression I have made using the Vis Sat Imagery over the Western Pacific as shown, the weakened circulation along the East China Sea with evident convective banding that is occurring in aide of the system. To the far right, huge thunderstorms spawned by a passing Front pushes the La Niña-Easterlies well into Eastern Philippines. Image Credit: Digital-typhoon."

The Joint Typhoon Warning Center (JTWC) based in Pearl Harbour, Hawaii Island, USA uses another methodology, the “Saffir-Simpson Hurricane Scale,”  now this is anchored on the actual wind speed acceleration averaged over a 1-minute period, at 10 m (33 ft) above the ground.

Fig. 3.0 "MLSP readings indicate the confined vorticity remains offshore, and stronger gust constrained along the Southern edge of Tropical Storm 02W/PAKHAR at the moment. Image Credit: CIRA."

One’s failure to comprehend these variations add to the growing confusion which agencies of the two should prevail.  I hope putting up this issue now give due understanding of the difference between the readings, even I to date tend to miss some of this, frankly speaking!

Will Tropical Storm 02W/PAKHAR Again Intensify?

The answer is a resounding yes, considering the existence of low shearing environment and the favourable “Sea Surface Temperature” (SST) across the East China Sea.  I am not using the word, West Philippine Sea, or a.k.a. South China Sea because the matter now is beyond our territorial seas (Chuckle).

Since the system has reached its peak so to speak, in the meteorological aspect, we call it “Diurnal Maximum,” as indicated by the JTWC in its 2100Z bulletin, wherein a certain Tropical Cyclone has reached its peak intensity for a 24-hour period.  This refers also on the temperature that occurs after midday which maximum heat can be obtained in a considerable time, and vis-a-vis, the minimum before the Sun hits the horizon early in the morning.

In addition to this, the various factors could also be attributed to change in relative humidity at a given time, the clouds that feed and wrap around the convective towering cloud tops or the anvil thunderstorms that give these Tropical Cyclone a finite source of moisture and adequate amount of heat, equivalent to energy.

Fig. 4.0 "A NOAA eTrap indicate the rainfall totals within a 24-hr period as the system persists at East China Sea. Image Credit: NOAA."

Talk about energy, the Sun and the heat radiated from the surface of the Sea can also affect a storm’s life, and oh, before I forget, the precipitation or the rains that rise and fall within the clouds, it’s called “Condensation” and the rate of “Evaporation.”  These are all essential to a Tropical system.  The stages that undergone feeds into a system like a conveyor belt, which I believe it could have definitive impact on the “Atmospheric Pressure,” that can only be found inside the core of the Tropical Cyclone.

Fig. 5.0 "I made this impression I got from NASA Goddard Space Flight Center through Rob Gutro's article at NASA Hurricane Page. I give credit to the efforts made by NASA/SSAI, Hal Pierce. Thanks a million, guys!"

To what extent did our storm lose steam? We will find out later this afternoon if our discussion here of a gradual intensification phase holds water!  In the meantime,  I am signing off for more of these a bit later tonight.  Nonetheless, we’ll all keep a close eye on this one as it maintains its course, though stationary at times, it has been generating a lot of precipitation back here in the Philippines for quite some time now.

Also, my fellow “Kababayans” in flood-ravaged towns of Mindoro Occidental, Bicol Region and parts of Capiz nearest to my location should take a look into the upcoming thunderheads that hover above us.  Right now I have been observing large thunderstorm anvils shooting into the atmosphere sending rumbling thunder ahead of the thunderstorms that could come at any moment soon!

This has been your Weatherguy hailing from the Philippines, Mabuhay! =)

With data from NOAA, NASA, CIRA, JTWC, JMA, HKO, NRL Mry and Typhoon2000.ph

(Note: If you have queries, email me at amanzan@smartbro.net or through–>weatherguyadonis@theboplive.net)